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At least 1,225 records · Page 68Linked to original sources
PubMed2005

[Treatment of condylar fracture by external pterygoid muscle-condyle anatomical reduction and internal rigid fixation with mini titanium plates].

PURPOSE: To investigate the surgical indications, procedures and treatment outcomes of condylar fracture by external pterygoid muscle-condyle anatomical reduction and internal rigid fixation with mini titanium plates. METHODS: Patients with dislocation of the condylar head, fracture of the condylar neck and subcondylar neck (the degree of displacement greater than 30 to 45) and decreased vertical height of the ramus (greater than 4 to 5mm) were included in the study. Modified aural-temporal stick-shaped incision or retromandibular approach was adopted in 23 cases with 28 condylar fractures. The fractures were treated by external pterygoid muscle-condyle anatomical reduction and internal rigid fixation with mini tension band titanium plates. All the patients were re-examined and evaluated 3 to 6 months after surgery in respects of facial symmetry, mouth opening, types of mouth opening, occlusion and mastication. RESULTS: All the patients had symmetrical face, mouth opening increased from 26.7+/-7.2 (before surgery) to 38.4+/-5.6 (3 months after surgery) and 37.2+/-4.5 mm(6 months after surgery). 2 patients with postoperative malocclusion had intermaxillary distraction for 1 week and their occlusion returned to normal. Radiographic check-up showed the condyle and titanium plates without displacement. No absorption was noted on the condylar surface. The patients had normal mastication. 2 patients with temporal facial paralysis recovered 3 months after conservative therapy. CONCLUSION: Treatment of condylar fracture by external pterygoid muscle-condyle anatomical reduction and internal rigid fixation with mini titanium plates in selected patients is an effective procedure for recovery of anatomical positions and masticatory function. Supported by Research Fund from Science and Technology Bureau of Jining city.

Bone Plates↗
PubMed2006

Gigantic tongue lipoma: a case report.

Lipomas are among the most common tumors of the human body. However, they are uncommon in the oral cavity. In the oral cavity they present as a slow growing, painless, and asymptomatic yellowish submucosal mass. Surgical excision is the treatment of choice with recurrence not expected. They have been known to grow to large sizes causing mastication and speech difficulties. The usual lesions consist of a well circumscribed, lobulated mass of mature fat cells. In other situations the covering mucosa becomes ulcerated and presents difficulties in diagnosis. The present report is of a patient who presented with a gigantic lipoma on the tip of the tongue which had been present for 3 years. She now had difficulty with speech and mastication as the tongue tumor now completely filled the oral cavity. An incision biopsy confirmed the tumor as lipoma. The tumor was surgically excised with restoration of normal tongue function, speech and masticatory capacity. Histopathologic examination of the excised tumor confirmed that it was a lipoma.

Female↗
PubMed1991

Electrophysiologic investigation of mandibular nerve injury.

Isolated lesions of the mandibular branch of the trigeminal nerve have only rarely been reported. We report the occurrence of an isolated lesion of the mandibular nerve associated with a unilateral mandibular fracture, and its substantiation electrophysiologically. A 65-year-old man was involved in a motor vehicle accident resulting in multiple fractures, including a unilateral mandibular fracture and temporomandibular joint dislocation. No evidence of intracranial pathology by CT scan was noted and the neurologic examination was nonfocal except for dysfunction of the mandibular nerve ipsilateral to the fracture site. Bilateral facial nerve latency and blink reflexes were normal. EMG evaluation of the muscles of facial expression and mastication demonstrated denervation confined to the muscles innervated by the mandibular branch of the trigeminal nerve. In patients complaining of facial sensory dysfunction, malocclusion, or weakness of muscles of mastication after mandibular fracture, an electrophysiologic examination can assist in evaluating cranial nerve integrity.

Aged↗
PubMed1990

Malocclusion.

Less than ideal interarch occlusal relationships rarely if ever cause significant untoward effects on the masticatory system. Parafunctional habits (such as bruxism and clenching) are responsible for excessive occlusal wear, fractured teeth, tooth mobility, the periodontal lesion of trauma from occlusion, fractured restorations, myofascial pain involving the muscles of mastication, and painful TMJs. Correction of the malocclusion with orthodontic procedures, restorative procedures, or occlusal adjustment by selective grinding will not control the parafunctional habits. Myofascial pain originating from the muscles of mastication is in an overwhelming number of cases a self-limiting problem. Therapy for this problem should not bring about any permanent physical changes to the patient's interarch occlusal relationships.

Bruxism↗
PubMed1989

HRP-labeled masticatory neurons in the rat trigeminal mesencephalic nucleus: a light and electron microscopic study.

The neurons innervating the muscles of mastication were labeled retrogradely with horseradish peroxidase (HRP) which was injected into each muscle of mastication of the rats. The TMB-HRP labeled neurons were for light microscopic and DAB-HRP labeled neurons for electron microscopic study. Many HRP-labeled mesencephalic neurons were observed in the trigeminal mesencephalic nucleus (TMEN) after HRP injection in jaw-closing muscles (JCM). On the other hand, no labeled neurons were found following the application of HRP to the lateral pterygoid and the anterior belly of the digastric muscles, with the exception of a very few from the mylohyoid muscle. The latter three muscles were jaw-opening muscles (JOM). The mesencephalic neurons of each JCM in the TMEN were rather randomly distributed, although they were concentrated more in the caudal region of this nucleus. These neurons were typically unipolar, with spherical to oval perikarya. Each neuron had a single process which coursed caudolaterally to join the mesencephalic tract of the trigeminal nerve. Ultrastructurally, mesencephalic masticatory neurons had a rather regular nucleus locating either centrally or eccentrically in the perikaryon, which is rather plump. The cytoplasm was endowed with very well developed Golgi apparatus and rough endoplasmic reticulum. Neurofilaments, varying in number, intermingled mostly with the Golgi apparatus in the cytoplasm. Somatic spines were frequently observed; however, synapses abutting upon the soma were few. Macula adherens-like structures were occassionally encountered in the contact zone between two cells.

Animals↗
PubMed1989

Facial musculoskeletal asymmetry in hemifacial microsomia.

Computer-assisted medical imaging--transaxial computed tomography (CT) scans and three-dimensional surface reconstructions--was used to study the muscles of mastication and their osseous origins and insertions in 24 patients with untreated unilateral hemifacial microsomia (HFM). The relationship between the volume of a muscle of mastication and the shape and size of its origin and insertion in such patients varies widely. Comparison of mean volumes of specific muscles documents a statistically significant decrease among patients who have moderate to marked mandibular dysmorphology as compared with those with minimally dysmorphic mandibles. This study supports the hypothesis that the shape and size of the mandible are related to the muscles that originate and insert upon it. However, the variation among individual patients means that assumptions regarding muscle mass and, in turn, function cannot be made regarding an individual patient on the basis of osseous dysmorphology that has been demonstrated on skull radiographs alone.

Adolescent↗
PubMed1989

[Differentiation of the dormouse Eliomys quercinus (Linnaeus 1766) fro the murid Mus caroli (Bonhote 1902) based on the masticatory muscles].

Investigated were the masticatory musculature of the murid, Mus caroli, and the glirid, Eliomys quercinus. Differences between both species could be found, which includes different mastication. Mus caroli eats mixed food. The masticatory musculature admits mainly antero-posterior mandibular movements with a minimal transverse component. The food of Eliomys quercinus exists of mainly insects. The masticatory muscles, in particular the M. pterygoideus internus and the well developed M. zygomaticomandibularis, pars posterior, include high frequency of lateral movements between mastication.

Animals↗
PubMedDate not supplied

[Periods of the morphofunctional status of the normal dentomaxillary system and in pathology].

The P.K. Anokhin's theory of functional systems provided a basis for differentiation of 6 periods of morphofunctional state of maxillodental system over the human life span. In each period, the functional conditions of mastication are viewed in the framework of relationship of morphology and function of mastication apparatus under the coordinating influence of the central nervous system.

Aging↗
PubMed1988

[Sex dimorphism of quantitative parameters of the masticatory muscles and skull of the rabbit].

The dry weight of the muscles of mastication and the size of the skull in the rabbit were studied from the 45th to the 225th d of life. Sexual dimorphism in the dry weight of the muscles of mastication appeared after the 100th d, the weight being higher in the case of the males. Sexual dimorphism of the skull affected only the zygomatic arch, the dimensions of the zygomatic arch in the male being greater than in the female from the 120th d on. The 2 differences are considered in relation to each other.

Animals↗
PubMed1988

Movement and function of mandible--a simplified mechano-morphological model of mandible.

It is an obvious fact that the shape of mandibles and its change are much concerned with the force vector of mastication muscles. In reference to the shape of mentum, however, it is yet inexplicable up to the present that the human mentum is such toughly shaped as being bearable against the force induced by mastication. In this paper, the authors show their three-dimensional mechanics model for the analysis in strength and they indicate that this model is suitable to explaining the shape.

Humans↗
PubMed1986

L-thyroxine, cortisol, and diet affect the postnatal development of the facial part of the skull in developing rats.

In rats, the effects of L-thyroxine (T4; 0.2 micrograms/g body weight), hydrocortisone (HC; 5 micrograms/g body weight) and mastication on the postnatal development of the facial part of the skull were examined. Administration of T4 and/or HC to rats for 5 consecutive days from day 5 after birth induced a precocious increase in the ratio of the facial length to the head length. The effects of these hormones decreased with the progression of weaning, and after the 20th postnatal day, the hormones had no effects on the postnatal development of either (facial and head) part of the skull. Moreover, these hormones played an additive role in the growth of facial part. On the other hand, continuous suckling from birth to the 30th postnatal day caused a significant decrease in the ratio of the facial length to the head length. These results suggest that increases in the circulating levels of T4 and HC in suckling rats and mastication in the weaning period are involved in development of the postnatal development of the facial part of the skull.

Aging↗
PubMed1980

Number and distribution of muscle spindles in the masticatory muscles of the rat.

The frequency and distribution of muscle spindles in the muscles of mastication of the rat have been studied. The average number of spindles found was 110 in the masseter, 75 in the temporalis and 25 in the medial pterygoid muscle, the spindles being predominantly in the medial parts of these muscles. No muscle spindles were found in the lateral pterygoid or posterior digastric muscle, and only isolated spindles were found in a few of the anterior digastric muscles. These differences between the jaw-closing and the jaw-opening muscles are intriguing and ask for further investigation of the role of the muscle spindles in mastication.

Animals↗
PubMed1980

[Adenocarcinoma developing in a non-functioning tuberculous kidney. One case (author's transl)].

The authors report a case of necrosed carcinoma oif the kidney presenting clinically with fever and a large abdomino-lumbar palpable mass and developing thirty years after functional exclusion of the kidney by tuberculosis. The two particular features were: displacement by the tumour or calcifications in this known mastic kidney, and the poor vascularisation of a necrosed tumour irrigated by an artery of small calibre. The association of tuberculosis and carcinoima, although rare, is no less well known: discovery of a carcinoma in a nephrectomy specimen (for tuberculosis), discovery of tuberculosis in the parenchyma around a carcinoima of the kidney. The rarest possibility remains that of development of a carcinoma of the kidney in a kidney non-functioning and mastic for years, but is sufficiently rare not to be an argument in favour of the excision of all non-functional tuberculous kidneys after adequate antituberculous therapy.

Adenocarcinoma↗
PubMed1995

Enamel rehardening by bread consumption.

PURPOSE: To investigate the in situ rehardening effect by white or whole-meal bread on softened enamel. MATERIALS AND METHODS: Twelve volunteers wearing orthodontic removable appliances participated in this study. The intraoral test was chosen for measuring microhardness of enamel slabs inserted into the dental appliance. Average microhardness of enamel was calculated at three stages: At start (baseline), after exposing the enamel slabs to a citrus beverage (pH 3.4) for 30 minutes in vitro as a softening agent, followed by intraoral exposure for a duration of 5 minutes to stimulated secreted saliva by parafilm chewing (control), or to 15g white- and wholemeal-bread mastication respectively (experimental). RESULTS: A significant rehardening of the softened enamel surfaces took place following mastication of the two bread samples and salivary secretion. The differences in the rehardening potentials of the bread samples as compared to that of saliva were not significant. From the conditions chosen for the experiment, there was no sufficient evidence to support the hypothesis that bread eating with calcium and phosphate concentrations at the existent levels will afford a significant greater rehardening than saliva alone.

Adult↗
PubMed1994

[The electromandibular kinesiograph in cleft lip and palate with crossbite].

Through the comparative study of 29 unilateral cleft lip and palate patients with crossbite and 29 crossbite patients with MKG we find some features of tracks in the cleft patients as follows: (1) The protrusive distance was larger and the track became less steep; (2) Occlusal interference occurred frequently, the incidence was about 65.5%; (3) The interocclusal rest space was larger; (4) 93.1% of the patients was unilateral mastication, 82.7% of them used the health side. The masticatory tracks were not concentrative and the range of lateral movements in mastication was small; (5) 75.86% of the patients presents one or two kinds of TMJDS symptoms, it should not be overlooked.

Adolescent↗
PubMed1993

[Masticatory values of dental prostheses anchored to depulped teeth].

The progress of conservative and surgical treatment of pulpless teeth has increased the number of pulpless teeth within prothetic restorations. There is a dilemma about masticatory values of such teeth and about the maximum load they can bear, that is, what masticatory values the denture anchored to them will have. Tooth values were measured by gnatodynamometry. We used gnatodynamometer with electroresistant metal measurement strips whose deformity is proportional to the force which the tooth, namely, the denture, bears. Measurements were carried out on a sample of 33 pulpless teeth, that is, on the almost same number of dentures anchored to the teeth. The measured pulpless teeth showed lower values than control teeth. The control group comprised normal teeth of the same subject, the sam jaw, which neutralized the problem of individuality. After the prothetic reconstruction by which the tooth regained its function, we checked mastication values again, this time the values of the dentures anchored to the pulpless teeth. We can conclude that pulpless teeth have lower values than vital ones. The lower values resulted also from their dysfunction. Prothetic reconstruction increases mastication values of pulpless teeth, but they never reach the values of controls, namely, of vital teeth.

Bite Force↗
PubMed1994

Enamel rehardening with cheese in irradiated patients.

Radiotherapy of head and neck malignancies results in severe xerostomia which induces radiation caries. Hard cheese has potent anti-cariogenic effects, even with minimal salivary gland function. Eight patients irradiated for neck cancer volunteered for this study. The saliva flow rate varied between 0.0-0.15 ml/minute. In vitro etched enamel slabs, prepared from human teeth, were exposed intraorally to parafilm stimulated salivary secretion for 5 minutes or, alternatively, to cheese compounds and saliva due to masticating 20 gm hard cheese for 5 minutes. Microhardness measurements were carried out on the enamel surface at start (baseline), after etching and after rehardening. Stimulated saliva or cheese compounds and saliva, due to mastication, induced rehardening of surface enamel in both, non-irradiated and irradiated subjects. The rehardening was significantly increased in the irradiated group consuming cheese as compared to rehardening by stimulated saliva only and not significantly less of that achieved in non-irradiated subjects. Rehardening achieved with stimulated saliva in irradiated patients was of a borderline-significant lower degree in comparison to non-irradiated subjects. The reduced rehardening capacity of a decreased saliva flow in irradiated patients may be complemented by cheese compounds. For xerostomic patients, hard cheese consumption may be regarded as effective to keep initial caries under control.

Cariostatic Agents↗
PubMed1993

Comparative study of craniofacial morphology in Japanese and Australian aboriginal populations.

A metric study of 71 Japanese and 106 Australian aboriginal precontemporary crania was undertaken using direct measurements and cephalograms. Compared with Australian aboriginals, the Japanese are characterized by smaller cranial length, cranial base length, nasal floor length, palatal length, mandibular dimensions (except symphysis height), facial depth, posterior face height, and facial profile angle and larger cranial breadth and height, maxillary breadth, palatal breadth, anterior face height, and occlusal and mandibular plane angles. These differences confirm the previously described brachycephalic tendency in aboriginals and the dolichocephalic form in the Japanese. The differences are also consistent with the expected functional differences between the Australian aboriginal hunter-gatherer group masticating more resistant food with larger, more anteriorly located, more powerful masseter muscles and the Japanese group masticating less resistant food with correspondingly less robust masticatory musculature. The results highlight the differences in craniofacial morphology between groups with different genetic backgrounds subjected to significantly different environmental influences.

Adolescent↗